Metabolic syndrome is a combination of several metabolic abnormalities that coexist, including obesity, insulin resistance, hypertension and dyslipidaemia. These metabolic abnormalities not only increase the risk of cardiovascular disease, but are also closely associated with metabolic diseases such as type 2 diabetes, fatty liver disease, and many types of cancer. With the prevalence of metabolic syndrome and its complications increasing year by year, how to effectively prevent and treat metabolic syndrome has become a major challenge for global public health. In recent years, metabolomics, as a high-throughput analytical technique to study metabolites in organisms, has been gradually applied to the study of metabolic syndrome and related metabolic diseases. Metabolomics can comprehensively depict the metabolic state of an organism and its dynamic changes, which provides a new perspective for revealing the pathological mechanisms of metabolic syndrome and searching for potential biomarkers. Through in-depth analysis of metabolomics data, researchers are able to better understand the complex pathological process of metabolic syndrome and provide a scientific basis for the development of personalised treatment and intervention strategies. Surgical intervention is a common treatment for patients with metabolic syndrome combined with metabolic diseases. However, postoperative metabolic status and disease remission are affected by a variety of factors, and the relevant mechanisms have not been fully clarified. Metabolomics-based approaches can systematically analyse the changes in metabolites before and after surgery, explore the key factors affecting postoperative remission, and reveal their underlying mechanisms. These studies can not only optimise the surgical treatment plan, but also provide an important theoretical basis for postoperative management.

This study will include patients with a diagnosis of metabolic syndrome combined with one or more metabolic disorders (e.g., type 2 diabetes mellitus, fatty liver disease, hypertension, etc.) who are determined to be on the verge of undergoing relevant surgical procedures. Patients will be categorised into patients with comorbid hypertension, patients with comorbid diabetes mellitus and patients with comorbid fatty liver disease according to their comorbid metabolic diseases. Basic preoperative information was collected, and blood and stool were collected for hormone testing and metabolomics measurements before surgery. Comparison of metabolic disease remission after surgery was performed to evaluate the efficacy. To analyse the effects of preoperative and postoperative metabolomics and hormonal changes on metabolic disease remission in patients with metabolic syndrome.

Inclusion Criteria:

• age ≥18 years;
• diagnosis of metabolic syndrome and combination of one or more metabolic diseases (e.g., type 2 diabetes mellitus, fatty liver disease, hypertension, etc.);
• identification of impending related surgical treatment;
• willingness to participate in this study and sign an informed consent form;
• complete clinical data.

Exclusion Criteria:

• Patients suffering from other serious systemic diseases (e.g., severe heart disease, renal insufficiency, liver cirrhosis, etc.) or malignant tumours;
• patients with acute diseases such as acute infections, acute myocardial infarction, acute stroke, etc.;
• patients who are on medications that may significantly affect their metabolic status (e.g., hormonal drugs, potent immunosuppressants, etc.);
• patients who cannot ensure compliance or are unwilling to cooperate with the study requirements;
• patients with Serious psychological disease or cognitive dysfunction, unable to understand the content of the study or cooperate with the study operation;
• Incomplete clinical data.

All adult patients diagnosed with metabolic syndrome and undergoing bariatric surgery at the study centre.